72,131 research outputs found
Wess-Zumino Model on Bosonic-Fermionic Noncommutative Superspace
In our previous paper we construct a renormalizable Wess-Zumino action on
BFNC superspace at the second order approximation of noncommutative parameters.
The action contains about 200 terms which are necessary for renormalization. By
removing chiral covariant derivatives and chiral coordinates we found that the
BFNC Wess-Zumino action can be transformed to a simpler form which have
manifest 1/2 supersymmetry. Based on this discovery, we can extend the BFNC
Wess-Zumino action to the all order of noncommutative parameters. At first we
introduce global symmetries, then obtain divergent operators in the effective
action by using dimensional analysis, the next step is to construct all
possible BFNC parameters, at the end we combine the BFNC parameters with the
divergent operators. We present the explicit action up to the fourth order of
noncommutative parameters. Because the action contain all possible divergent
operators, it is renormalizable to all order in perturbative theory.Comment: 29 page
Covariant Quantization of BFNC Super Yang-Mills Theories and Supergauge Invariance
To construct renormalizable gauge model in Bosonic-Fermionic noncommutative
(BFNC) superspace, we replace the ordinary products of super Yang-Mills model
by BFNC star products. To study the renormalization property of the deformed
action, we obtain the one-loop 1PI effective action by using background field
method at the first order of BFNC parameters. We also verify the BFNC
supergauge invariance of the effective action. Because there are new terms in
effective action, the deformed action is not renormalizable. This imply that
additional terms should be added to the deformed action.Comment: 15 page
Optimal control for multi-parameter quantum estimation with time-dependent Hamiltonians
We investigate simultaneous estimation of multi-parameter quantum estimation
with time-dependent Hamiltonians. We analytically obtain the maximal quantum
Fisher information matrix for two-parameter in time-dependent three-level
systems. The optimal coherent control scheme is proposed to increase the
estimation precisions. In a example of a spin-1 particle in a uniformly
rotating magnetic field, the optimal coherent Hamiltonians for different
parameters can be chosen to be completely same. However, in general, the
optimal coherent Hamiltonians for different parameters are incompatibility. In
this situation, we suggest a variance method to obtain the optimal coherent
Hamiltonian for estimating multiple parameters simultaneously, and obtain the
optimal simultaneous estimation precision of two-parameter in a three-level
Landau-Zener Hamiltonian.Comment: 9 pages, 1 figure
CIF: Continuous Integrate-and-Fire for End-to-End Speech Recognition
In this paper, we propose a novel soft and monotonic alignment mechanism used
for sequence transduction. It is inspired by the integrate-and-fire model in
spiking neural networks and employed in the encoder-decoder framework consists
of continuous functions, thus being named as: Continuous Integrate-and-Fire
(CIF). Applied to the ASR task, CIF not only shows a concise calculation, but
also supports online recognition and acoustic boundary positioning, thus
suitable for various ASR scenarios. Several support strategies are also
proposed to alleviate the unique problems of CIF-based model. With the joint
action of these methods, the CIF-based model shows competitive performance.
Notably, it achieves a word error rate (WER) of 2.86% on the test-clean of
Librispeech and creates new state-of-the-art result on Mandarin telephone ASR
benchmark.Comment: To appear at ICASSP 202
Gradient estimates for divergence form elliptic systems arising from composite material
In this paper, we show that weak solutions to
divergence form elliptic systems are Lipschitz and piecewise provided
that the leading coefficients and data are of piecewise Dini mean oscillation,
the lower order coefficients are bounded, and interfacial boundaries are
. This extends a result of Li and Nirenberg (\textit{Comm.
Pure Appl. Math.} \textbf{56} (2003), 892-925). Moreover, under a stronger
assumption on the piecewise -mean oscillation of the leading
coefficients, we derive a global weak type-(1,1) estimate with respect to
Muckenhoupt weights for the elliptic systems without lower order terms.Comment: 34 pages, submitte
Multi-parameter Quantum Magnetometry with Spin States in coarsened measurement reference
We investigate the simultaneous estimation of the intensity and the
orientation of a magnetic field by the multi-parameter quantum Fisher
information matrix. A general expression is achieved for the simultaneous
estimation precision of the intensity and the orientation, which is better than
the independent estimation precision for the given number of spin states.
Moreover, we consider an imperfect measurement device, coarsened measurement
reference. For the case of the measurement reference rotating around the
axis randomly, the simultaneous estimation always performs better than the
independent estimation. For all other cases, the simultaneous estimation
precision will not perform better than the independent estimation when the
coarsened degree is larger than a certain value.Comment: 7pages,3 figure
Conformal Nets Associated with Lattices and Their Orbifolds
In this paper we study representations of conformal nets associated with
positive definite even lattices and their orbifolds with respect to isometries
of the lattices. Using previous general results on orbifolds, we give a list of
all irreducible representations of the orbifolds, which generate a unitary
modular tensor category.Comment: 25 page
Gradient estimates for divergence form parabolic systems
We consider divergence form, second-order strongly parabolic systems in a
cylindrical domain with a finite number of subdomains under the assumption that
the interfacial boundaries are and in the
spatial variables and the time variable, respectively. Gradient estimates and
piecewise -regularity are established when the leading coefficients
and data are assumed to be of piecewise Dini mean oscillation or piecewise
H\"{o}lder continuous. Our results improve the previous results in
\cite{ll,fknn} to a large extent. We also prove a global weak type-
estimate with respect to Muckenhoupt weights for the parabolic systems
with leading coefficients which satisfy a stronger assumption. As a byproduct,
we give a proof of optimal regularity of weak solutions to parabolic
transmission problems with or interfaces. This
gives an extension of a recent result in \cite{css} to parabolic systems.Comment: 41 pages. Submitte
Resonant Tidal Excitation of Oscillation Modes in Merging Binary Neutron Stars: Inertial-Gravity Modes
In coalescing neutron star (NS) binaries, tidal force can resonantly excite
low-frequency (< 500 Hz) oscillation modes in the NS, transferring energy
between the orbit and the NS. This resonant tide can induce phase shift in the
gravitational waveforms, and potentially provide a new window of studying NS
interior using gravitational waves. Previous works have considered tidal
excitations of pure g-modes (due to stable stratification of the star) and pure
inertial modes (due to Coriolis force), with the rotational effect treated in
an approximate manner. However, for realistic NSs, the buoyancy and rotational
effects can be comparable, giving rise to mixed inertial-gravity modes. We
develop a non-perturbative numerical spectral code to compute the frequencies
and tidal coupling coefficients of these modes. We then calculate the phase
shift in the gravitational waveform due to each resonance during binary
inspiral. We adopt polytropic NS models with a parameterized stratification. We
derive relevant scaling relations and survey how the phase shift depends on
various properties of the NS. We find that for canonical NSs (with mass M =
1.4M_sun and radius R = 10 km) and modest rotation rates (< 300 Hz), the
gravitational wave phase shift due to a resonance is generally less than 0.01
radian. But the phase shift is a strong function of R and M, and can reach a
radian or more for low-mass NSs with larger radii (R > 15 km). Significant
phase shift can also be produced when the combination of stratification and
rotation gives rise to a very low frequency (< 20 Hz in the inertial frame)
modified g-mode. We also find that some inertial modes can be strongly affected
by stratification, and that the m = 1 r-mode, previously identified to have a
small but finite inertial-frame frequency based on the Cowling approximation,
in fact has essentially zero frequency, and therefore cannot be excited.Comment: 18 pages, 11 figures, 4 table
Disruption of Planetary Orbits Through Evection Resonance with an External Companion: Circumbinary Planets and Multiplanet Systems
Planets around binary stars and those in multiplanet systems may experience
resonant eccentricity excitation and disruption due to perturbations from a
distant stellar companion. This "evection resonance" occurs when the apsidal
precession frequency of the planet, driven by the quadrupole associated with
the inner binary or the other planets, matches the orbital frequency of the
external companion. We develop an analytic theory to study the effects of
evection resonance on circumbinary planets and multiplanet systems. We derive
the general conditions for effective eccentricity excitation or resonance
capture of the planet as the system undergoes long-term evolution. Applying to
circumbinary planets, we show that inward planet migration may lead to
eccentricity growth due to evection resonance with an external perturber, and
planets around shrinking binaries may not survive the resonant eccentricity
growth. On the other hand, significant eccentricity excitation in multiplanet
systems occurs in limited parameter space of planet and binary semimajor axes,
and requires the planetary migration to be sufficiently slow.Comment: 15 pages, 16 figure
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